deep-sea vs seawater

deep-sea

adj
  • Of or related to open sea. 

  • Of, related to or located in the deeper part of the sea. 

  • Able to accommodate the largest ships. 

seawater

adj
  • Consisting of seawater. 

  • Associated in some way with seawater, or intended for dealing with seawater. 

noun
  • The saltwater of a sea or ocean. 

How often have the words deep-sea and seawater occurred in a corpus of books? (source: Google Ngram Viewer )